Lexicography

constructive algorithms, strings

Kirk and a Binary String (easy version)

brute force, greedy, strings

Guest Student

math

The Tower is Going Home

binary search, two pointers

Moving Both Hands

dp, graphs, shortest paths

The Parade

binary search, greedy

Roman Digits

brute force, combinatorics, dp, greedy, math

Wonderful Randomized Sum

greedy

How Many Paths?

dfs and similar, dp, graphs, trees

Ravioli Sort

implementation

Tyler and Strings

combinatorics, data structures, implementation

Buses Between Cities

implementation

Into Blocks (easy version)

data structures, dsu, greedy, implementation, two pointers

Chamber of Secrets

dfs and similar, shortest paths

Inna and Huge Candy Matrix

implementation, math

Rudolph and Mimic

constructive algorithms, implementation, interactive

Beautiful Subarrays

data structures, divide and conquer, strings, trees

Elimination

dp, implementation, math

Division + LCP (easy version)

binary search, data structures, dp, hashing, string suffix structures, strings

Fibonacci Strings

greedy, implementation, math, number theory

Workout plan

data structures, greedy

Pictures with Kittens (hard version)

data structures, dp

Intercity Travelling

combinatorics, math, probabilities

Antimatter

dp

Pasha and Phone

binary search, math

MEX vs MED

math, two pointers

Guess the K-th Zero (Hard version)

binary search, constructive algorithms, data structures, interactive

Marathon

implementation, math

Number of Triplets

binary search, brute force

Help Chef Gerasim

implementation, sortings

Minimax

constructive algorithms, greedy, strings

Extra-terrestrial Intelligence

implementation

World of Darkraft: Battle for Azathoth

brute force, data structures, sortings

Gluttony

constructive algorithms, greedy

Secret

constructive algorithms, implementation

Paths in a Complete Binary Tree

bitmasks, trees

Read Time

binary search, greedy, two pointers

Subsequences (hard version)

dp, strings

Lucky Queries

data structures

Unusual Entertainment

data structures, dfs and similar, dsu, shortest paths, sortings, trees, two pointers

Little Artem and Time Machine

data structures

New Year and Conference

binary search, data structures, hashing, sortings

Kuroni and the Score Distribution

constructive algorithms, greedy, implementation, math

Clothes

brute force

Marbles

bitmasks, dp

Credit Card

data structures, dp, greedy, implementation

Delete Them

constructive algorithms, implementation

String Manipulation 1.0

*special problem, binary search, brute force, data structures, strings

Calendar

brute force, implementation

OpenStreetMap

data structures, two pointers

Nearest Fraction

brute force, implementation, two pointers

Balls and Boxes

constructive algorithms, greedy, implementation

Vlad and the Mountains

binary search, data structures, dsu, graphs, implementation, sortings, trees, two pointers

Send Boxes to Alice (Hard Version)

constructive algorithms, greedy, math, number theory, ternary search, two pointers

Prime Number

math, number theory

New Year's Puzzle

brute force, dp, graph matchings, greedy, sortings

Skyline Photo

data structures, divide and conquer, dp

Mysterious strings

*special problem, implementation

Rudolf and Subway

constructive algorithms, dfs and similar, graphs, shortest paths

System Administrator

graphs

Closest Equals

*special problem, data structures

Vlad and Trouble at MIT

dfs and similar, dp, flows, graphs, greedy, implementation, trees

Turn Off The TV

data structures, sortings

Pavel and barbecue

constructive algorithms, dfs and similar

My pretty girl Noora

brute force, dp, greedy, math, number theory

Ciel and Duel

dp, flows, greedy

Let's Play the Words?

data structures, hashing, implementation, math

Clear Symmetry

constructive algorithms, dp, math

Single-use Stones

binary search, flows, greedy, two pointers

Array Shuffling

constructive algorithms, graphs, greedy

Permutation Game

implementation

Robin Hood

binary search, greedy

Vasya and Good Sequences

bitmasks, dp

Bank Hacking

constructive algorithms, data structures, dp, trees

Blood Cousins Return

binary search, data structures, dfs and similar, dp, sortings

Monsters

brute force, data structures, dfs and similar, dsu, graphs, greedy

Kirk and a Binary String (hard version)

data structures, greedy, math, strings

Tennis Game

binary search

Sergey and Subway

dfs and similar, dp, trees

Vasya and Beautiful Arrays

brute force, dp, number theory

Labyrinth

dfs and similar, graphs

Salyg1n and Array (hard version)

constructive algorithms, interactive

Flying Sort (Easy Version)

dp, greedy, two pointers

Perfect Triples

bitmasks, brute force, constructive algorithms, divide and conquer, math

Elections

greedy

Unusual Sequences

bitmasks, combinatorics, dp, math, number theory

Coprime Subsequences

bitmasks, combinatorics, number theory

Centroids

data structures, dfs and similar, dp, graphs, greedy, trees

Message

brute force

Five Dimensional Points

brute force, geometry, math

Merge Sort

constructive algorithms, divide and conquer

No Palindromes

brute force, constructive algorithms, divide and conquer, greedy, hashing, implementation, math, strings

Make k Equal

greedy

Minimal Labels

data structures, dfs and similar, graphs, greedy

Exposition

binary search, data structures, dsu, trees, two pointers

Flag

brute force, combinatorics, dp, implementation

Expand the Path

brute force, combinatorics, data structures, implementation, math

Maximize!

binary search, greedy, ternary search, two pointers

Winter Is Coming

dp, greedy, sortings

Doremy's Drying Plan (Easy Version)

brute force, data structures, dp, greedy, sortings